Lubricating and sealing means for rotary pumps



Get 28, 192%. 1,513,659

a. w. WARDWELL v LUBRICATING AND SEALING MEANS FOR ROTARY PUMPS Filed001;. 24 192 3 2 Sheets-Sheet l INVENTOR ATTORNEY ch28, 1924,. G. W.WARDWELL LUBRICATING AND SEALING MEANS FOR ROTARY PUMPS Filed Oct. 24.1923 2 Sheets-Sheet 2 WHHHHHIIHI INVENTOR BY W 6;: Mfi ATTORNEY PatentedD ck. 28, 1924.

GEORGE W. WARDWELL, OF SOUTH NORWALK, CONNECTICUT, ASSIGNOR TO THE HILLCOMPRESSOR AND PUMP 'COMPANY, OF NEW YORK, N.

DELAWARE.

Y., A. CORPORATION OF LUBRICATING AND SEALING MEANS FOR ROTARY PUMRS.

Application filed October '24, 1923. Serial No. 670,496.

To all whom it may concem:

Be it known that I, GEORGE W. WARD- WELL, a citizen of the UnitedStates, residing at South Norwalk in the county of Fairfleldand State ofonnecticut, have invented a new and useful Improvement in Lubricatingand Sealing Means for Rotary Pumps, of which the followingis aspecification.

This invention relates to rotary pumps for pumping fluids of the typehaving an nternally toothed driving gear engaged w th anexternally-toothed driven gear of 'a-=d1fferent number of. teeth.

The object of this invention is to rovide a very simple means forlubricating the wearing surfaces between the gears and walls of the pumpchamber, the circulation of the lubricating medium being automatlcallyeffected by the operation of the pump and rovidin a fluid seal forthejoints whic will re uoe friction and prevent leake age, across thefaces of the gear teeth of the fluid pum d without danger of choking thepump wit lubricant.

' This object is attained in the present mstance by forming a duct forthe passa e of lubricant through the rotor from a lubricant holding anddischarge pressure cavity back of the rotor to a central cavity in frontofthe rotor, whereby lubricant will be forced to the front of the rotorfrom which locality it will flow '-out between thefaces of the gears andthe face of the end of the pumping chamber in which the gears and rotorare located. I

In the accompanying drawings Fig. 1

shows a central longitudinal section of a pump constructed according tothis invention. Fig. 2 shows a transverse section of the ump on theFlane indicated by the dotv ted line 22 on 1g. 1.

The casing 1 wl lch isgenerally. circular in outline containsac'ylindrical pumping chamber 2 that is closed at one end by a head 3which is fastened to the casing by any suitable means. The casing has anmtake passage 4 on one side and a discharge passage 5 on the other side,while the head has an intake port 6 leading from the intake passage tothe pumping chamber and a discharge port 7 leading from the pumpingchamber to the discharge passage. Rotatably fitting and having a slightmovement axially in the pumping chamber is a rotor 8. 65 The hub 9 ofthe rotor ismounted on antifriction bearings 10 the inner ring 11 ofwhich is fasteneg tothe hub while theouter race ring 12 is tted so thatit may have a slight axial movement in the casing. The driving shaft 13is splined in the hubof the rotor so that while the shaft will turn therotor it will not interfere with the axial movement of the rotor. Fastened in the rotor is an internally toothed gear 14 and engaging theteeth of this gear are the teeth of an externally toothed gear 15. -Theexternally toothed gear is mounted on anti-friction bearings 16-arranged in a cavity 17 in Y i the gear and supported by a stud 18fastened toothed gear. One of these gears has more teeth than the otherand they coact in a well known manner to effect the pumping or comepression of fluids. I

A spring 19' is arranged in a cavity 20 that communicates with thepumping cham- 7 her, such manner that it thrusts against Y the outerrace ring 12 and through the bearing presses the rotor and the faces ofthe pumpmg gears'against the inner face of the head. 1 Lubricant isintroduced into this cavity. Leadin from the reservoir 21 into which thefluid is pumpedfllo the cavity containin the spring is a pipe 22. Thefunction 0 this connection i to admit discharge pressure to the.cavityand permit it to-be-ex- 9o erted on the back ofthe rotor. Thisconnection also is adapted to conduct back lubri-v cant which has beenforced 'throu h the joints of the pump and out throught e dischargepipe. A common type offland packing 23 is arranged in the end 0 thecasing to prevent leakage from the spring cavity around the drivingshaft.

lfn order to accomplish the object of-this invention a duct or passage24 is made through the hub of the rotor from the pressure cavitycontaining the spring back of the rotor to the cavity containing thehearing for the externally toothed gear in front of the rotor. When thepump is running the centrifugal force of the externally toothed gear andthe fact that it wipes around on the face of the head is suflicient toallow just the right amount of lubricant to work out on the faces of thegears and also; between the contacting faces of the teeth. The lubricantwhich escapes passes through the discharge and is returned to thepressure chamber so as to furnish a continuous supply of lubricant underpressure. When the pump stops even though there is pressure on thelubricant in the cavity the lubricant will not flow into the inletspaces between the teeth for with pressure behind the rotor the faces ofthe teeth are in tight sealing position, with relation to the head, andthe externally toothed gear is in tight sealing position with relationto the inner face of the rotor. When the pump is started the flow oflubricant is automatically started and when the pump stops the flow oflubricant stops, but the lubricant remains in position to not onlylubricate the wearing faces but also to fluid seal the joints.

The invention claimed is 1. A rotary pump comprising a casing containinga pumping chamber, a head closing one end of the pumping chamber, saidhead having an intake to and discharge from said chamber, a rotorrotatable in and having an axial movement in said chamber, intermeshinginternally toothed and ex ternally toothed pumping gears in front of therotor, said internally toothed gear being fastened to the rotor, apressure cavity in the casing open to the back of the rotor, meansconnecting said pressure cavity with the discharge from the pump, and apassage extending axially through the rotor to a cavity in the center ofthe gears for admitting discharge pressure from the cavity back of therotor to the cavity in the center of the gears and permitting lubricantto flow from the cavity back of the rotor to the front of the rotor andwork out between the end faces of the gear teeth and the head end wallof the pumping chamber, to the discharge.

2. A rotary pump comprising a casing containing a pumping chamber, ahead closing one end of the pumping chamber, said head having an intaketo and discharge from said chamber, a rotor rotatable in and having anaxial movement in said chamber, intermeshing internally toothed andexternally toothed pumping gears in front of the rolor, said internallytoothed gear being fastened to the rotor, a pressure cavity in thecasing open to the back of the rotor, a spring located in said cavityand adapted to press the rotor forward, means connecting said pressurecavity with the discharge from the pump, and a passage extending axiallythrough the rotor to a cavity in the center of the gears for admittingdischarge pressure from the cavity back of the rotor to the cavity inthe center of the gears and permitting lubricant to flow from the cavityback of the rotor to the front of the rotor and work out between the endfaces of the gear teeth and the head end wall of the pumping chamber, tothe discharge.

3. A rotary pump comprising a casing containing a pumping chamber, ahead closing one end of the pumpin chamber, said head having an intaketo and discharge from said chamber, a rotor rotatable in and having anaxial movement in said chamber, intermeshing internally toothed andexternally toothed pumping gears in front of the rotor, said internallytoothed gear being fastened to the rotor, a pressure cavity in thecasing open to the back of the rotor, means connecting said pressurecavity with the discharge from the pump, bearings for the externallytoothed gear in a cavity in said gear in front of the rotor, and apassage extending axially through the rotor from the pressure cavity tothe bearings cavity for admitting discharge pressure from the pressurecavity back of the rotor to the bearings cavity in front of the rotorand permitting lubricant to flow from the cavity back of the rotor tothe front of the rotor and work out between the end faces of the gearteeth and the head end Wall of the pumping chamber, to the discharge.

4. A rotary pump comprising a casing con taining a pumping chamber, ahead closing one end of the pumping chamber, said head having an intaketo and discharge from said chamber, a rotor rotatable in and having anaxial movement in said chamber, intermeshing internally toothed andexternally toothed pumping gears in front of the rotor, said internallytoothed gear being fastened to the rotor, a duct conducting dischargepressure from the pump to the back of the rotor, and a passage extendingaxially through the rotor for conducting discharge pressure to the frontof the rotor and permitting lubricant to flow from the back of the rotorthrough the rotor to the front of the rotor and work out to thedischarge between the end faces of the gear teeth and the head end wallof the pumping chamber.

5. A rotary pump comprising a casing containing a pumping chamber, ahead closing one end of the pumping chamber, said head having an intake-to and discharge from said chamber, a rotor rotatable in and rename Yhavingan axial movement in said chamrotor, means connecting saidpressure cav-' ber, intermeshing internally toothed and exity with thedischarge from the pump, a

ternally' toothed pumping gears in front of cavity in front of therotor, bearin s in said N the rotor, said internally toothedi gearbefront cavity, and a passage cxten ing axi-- 5 ing fastened to therotor, a pressure cavity ally through the rotor and connecting said inthe casingback of the rotor, a spring in pressure cavity with saidbearings cavity. said cavity thrusting against the hack of the :EORGE W.WARDWELLJ

